When you don’t have any weapon near you to kill zombies then you must use the objects around you to prepare some unlucky moments for the undead, the same thing happens in Rolling Fall 2.
This game is classic. Every level is filled with several zombies who must be killed. If you push them from the screen or let some heavy objects lend on their heads you beat the level. Cut chains, create chain reactions or hit them straight into their heads. The difficulty isn’t exactly easy but everything can be solved.